1. Field of the Invention
The present invention relates to a water-quality detection device and a method for detecting the lifetime thereof, and more particularly, to an ion exchange resin tower and a detection method of the lifetime of the resin therein.
2. Description of Related Art
A water purification system is capable of removing impurities in water, including suspensions, particles, organics, microorganisms, electrolytes, and gases, etc., to improve the resistance of the pure water to a limit level, so as to ensure the high water purity. Generally, the resistance of pure water is substantially greater than 18 MΩ-cm, the higher the resistance is, the fewer the ions in the water are, that is, the higher the water quality is.
An ion exchange resin tower is a unit of the water purification system for removing ions from the water effectively. For example, a cation exchange resin is used to exchange cation functional groups with cations in the water, such as Ca2+ and Mg2+, so as to reduce the concentration of Ca2+ and Mg2+ in water. During the ion exchange process, the resin gradually adsorbs Ca2+ and Mg2+ and accumulates them to reach a certain amount to become saturated, and thus it cannot perform ion exchange any more, and at this time, the resin must be renewed, regenerated or replaced.
The lifetime of the resin is affected by many variations, for example, quality of pre-processed water, water flow in resin and so on. Therefore, if the resin is renewed according to the lifetime suggested by the manufacturer, it may be done prior to the saturation, and thus increasing the cost. Therefore, acquiring the exact time for the resin to get saturated is surely beneficial for reducing the cost.
As for the method of measuring the saturation of the resin, a method for obtaining the saturation of a resin by a probe disposed in a tank is provided in the prior art, in which the probe is used to detect the resistance of the water there around, when the resistance is lower than a certain default value, it indicates that the resin is saturated and fails to perform ion exchange, so the resin must be renewed.
However, as the probe is located in the tank, merely the saturation of the resin can be determined through using the resistance of the water, but the water cannot be sampled for further analysis about other chemical properties or physical properties. If the contaminations in the water cannot be detected by the probe, the deterioration of water quality caused by the contaminations that cannot be detected through the conventional method as well.